Exhaust paths associated with internal combustion engines typically include a variety of types of devices such as catalytic converters, exhaust heat recovery apparatus, mufflers and other equipment. If the exhaust gas passing along such exhaust paths and through such exhaust path equipment contains an excessive level of hydrocarbons the potential exists for damaging such equipment. For example, excessive hydrocarbons can result in exhaust gas which could combust along the exhaust path resulting in damage to associated exhaust path equipment. Further, if excessive hydrocarbons are passed through a device such as a catalytic converter it is possible that an excessive amount of heat may be generated therein resulting in damage to the catalytic converter. In many applications it is also necessary to assure that the level of hydrocarbons emitted are not excessive for environmental reasons.
Known internal combustion engines may include an exhaust gas probe which is capable of measuring the hydrocarbon content of such gas through relatively complex techniques. Use of probes employing such techniques can significantly increase costs associated with manufacturing and operating internal combustion engines.
Accordingly, the present invention is directed to overcoming one or more of the problems as set forth above.